A machine for finishing the tooth flanks of gear-shaped workpieces with an internal gear tool is known to comprise:
a) a main frame with a machine bed, PA1 b) a headstock and a tailstock with devices for rotatably driven mounting of the work to be machined, said devices being disposed on the machine bed, with the headstock adapted for controlled driving for movement in a Z-direction, that is, in the direction of the work axis, PA1 c) a slide system supported by the main frame and comprising two controlled-drive slides, of which the one is displaceable in a Y-direction, i.e., perpendicular to the axis of the work being machined, and the other in an X-direction, i.e., perpendicular to the Y- and Z-direction, PA1 d) a cradle supported by the slide system and holding a tool head adapted for angular setting about an axis perpendicular to the work axis, the tool head being disposed between the headstock and the tailstock, and PA1 e) an internal gear tool mounted in the tool head and allowing rotatable driving, with a controlled relative movement being provided in the Z-direction between the tool and the work.
The above machine is described in DE 43 23 935 C1 which corresponds to U.S. Pat. No. 5,443,338 to Huber et al. the disclosure of which is hereby incorporated by reference. This prior machine possesses a main frame having approximately the shape of a flat-lying T. The region corresponding to the cross bar of the T, on the machine front, forms a machine bed on which are disposed a headstock and a tailstock, both adapted for controlled driving to move in the direction of the work axis. Arranged in the other area of the main frame, extending to the rear, is a horizontal slide adapted for displacement and to be driven perpendicularly to the work axis. Arranged on the side of the horizontal slide facing the machine bed is a displaceable, driven vertical slide. On its side facing the machine bed, the vertical slide features a cradle accommodating a tool head in a manner allowing angular adjustment about a horizontal axis that is perpendicular to the work axis.
This prior machine is very rigid and, therefore, suited particularly for machining large workpieces. For mounting a workpiece, the headstock and the tailstock are displaced jointly on the machine bed. For reason of accessibility, the mounting or release position is located outside the work space, beyond the main frame region extending toward the rear. The clearance between the receiving/release position and the working position inside the machine amounts to approximately 700 mm. This displacement travel of the headstock makes itself felt with respect to the work changing time and requires an appropriate machine bed and, thus, an appropriate floor space for the machine.
The objective underlying the present invention is to create a machine suited for smaller workpieces, with the clearance between the workpiece receiving/releasing position and the working position being as short as possible so as to achieve a favorable ratio of work change times to machining times.
The inventional machine allows the arrangement of the receiving and releasing position of a workpiece in the machine within a relatively short distance from the machining position. The time required for the work movement between these two positions, therefore, is short and the machine bed can be configured relatively short.